engine light came on after timing chain replacment?

i have just replaced the timing chain with all the kit but i noticed the top gears were thinner than the old ones but this was supplied by the dealers saying it is the right kit for the car part number 93191271 i have a corsa c 1.2 sxi now the engine light has came on indicating to the crank sensor do i need to replace the crank sensor or have they supplied me with the wrong kit?